The present disclosure relates to a method of compensating for lens shading, and more particularly, to a method of calculating a compensation factor to compensate for lens shading due to the characteristics of an image capturing device, which requires a small amount of memory. According to an embodiment, a white image is captured, and a compensation factor is calculated using the characteristics of a lens shading pattern of the captured white image. According to another embodiment, a distribution of pixel values is approximated using an exponential spline function, and a compensation factor is calculated using the approximated distribution. In addition, a method and an apparatus for compensating for lens shading by using a calculated compensation factor are provided according to embodiments.
In general, when an image is captured using an image capturing apparatus including a lens system and an image capturing part, the lens system causes an optical loss in the periphery thereof, and thus, a shaded area, that is, an unevenly dark area is formed at the periphery of the captured image.
Various methods are used to compensate for lens shading. For example, all pixel values of an image may be measured and be corrected using the maximum pixel value, which may require a large amount of memory according to the size of an image. Moreover, as the amount of input data increases, a processing speed decreases. Other methods also require a large amount of memory.
The amount of memory is a main factor for evaluating mobile devices such as digital cameras or cellular phones including a camera. Devices requiring a large amount of memory may cause various issues.